﻿using System.Text;
using System.Text.RegularExpressions;

namespace Ln.Fram.Core.Helper;

public class RandomHelper
{
	public static string replaceBianLiang(string content)
	{
		content = content.Replace("{当前时间}", DateTime.Now.TimeOfDay.ToString());
		string[] bianliang = new string[] { "{随机字母}", "{随机数字}", "{随机汉字}" };
		Regex r;
		int count;
		string readstr = "";
		foreach (string str in bianliang)
		{
			count = (content.Length - content.Replace(str, "").Length) / str.Length;
			if (str == "{随机汉字}") readstr = RandChina(count);
			if (str == "{随机数字}") readstr = GenerateCheckCodeNum(count);
			if (str == "{随机字母}") readstr = GenerateRandomLetter(count);
			if (count > readstr.Length) count = readstr.Length;
			r = new Regex(str.Replace("{", "\\{").Replace("}", "\\}"));
			for (int i = 0; i < count; i++)
			{
				content = r.Replace(content, readstr.Substring(i, 1), 1);
			}
		}
		return content;
	}


	/// <summary>
	/// 随机生成字母
	/// </summary>
	/// <param name="Length"></param>
	/// <returns></returns>
	public static string GenerateRandomLetter(int Length)
	{
		char[] Pattern = new char[] { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z' };
		string result = "";
		int n = Pattern.Length;
		Random random = new Random(~unchecked((int)DateTime.Now.Ticks));
		for (int i = 0; i < Length; i++)
		{
			int rnd = random.Next(0, n);
			result += Pattern[rnd];
		}
		return result;
	}

	/// <summary>
	/// 随机生成数字
	/// </summary>
	/// <param name="codeCount"></param>
	/// <returns></returns>
	public static string GenerateCheckCodeNum(int codeCount)
	{
		int rep = 0;
		string str = string.Empty;
		long num2 = DateTime.Now.Ticks + rep;
		rep++;
		Random random = new Random((int)((ulong)num2 & 0xffffffffL) | (int)(num2 >> rep));
		for (int i = 0; i < codeCount; i++)
		{
			int num = random.Next();
			str = str + ((char)(0x30 + (ushort)(num % 10))).ToString();
		}
		return str;
	}

	/// <summary>
	/// 此函数为生成指定数目的汉字

	/// </summary>
	/// <param name="charLen">汉字数目</param>
	/// <returns>所有汉字</returns>
	public static string RandChina(int charLen)
	{
		int area, code;//汉字由区位和码位组成(都为0-94,其中区位16-55为一级汉字区,56-87为二级汉字区,1-9为特殊字符区)
		StringBuilder strtem = new StringBuilder();
		Random rand = new Random();
		for (int i = 0; i < charLen; i++)
		{
			area = rand.Next(16, 88);
			if (area == 55)//第55区只有89个字符

			{
				code = rand.Next(1, 90);
			}
			else
			{
				code = rand.Next(1, 94);
			}
			strtem.Append(Encoding.GetEncoding("GB2312").GetString(new byte[] { Convert.ToByte(area + 160), Convert.ToByte(code + 160) }));
		}
		return strtem.ToString();
	}
}
